Circular Expander for Treating Tubular Fabric

ABSTRACT

The aim of the invention is to provide a circular expander ( 1 ) that allows an easy-to-adjust, continuous passage of textiles while not impairing the quality of the passing tubular fabric ( 12 ). For this purpose, a magnetic bearing ( 8 ) is provided optionally at the inlet or outlet of the circular expander and a conventional roller bearing ( 9 ) is provided at the opposite end of the circular expander.

The invention relates to a circular expander for treating textile tubular fabric, which is integrated in a treatment unit and is held, suspended, in a vertical arrangement.

The circular expander consists of

a telescopically displaceable central carrier, on which outwardly spreadable supports are articulated, the supports being connected to elements for the longitudinal guidance of the tubular fabric,

a first device, formed at one end of the central carrier as a tubular fabric entry, for delivering the tubular fabric,

a second device, formed at the other end of the central carrier as a tubular fabric exit, for discharging the tubular fabric,

a lifting apparatus, engaging selectively on the first or the second device, for setting the size of the circular spread, and

an apparatus, operatively connected to the central carrier, for locking the set size of the circular spread.

Circular expanders having a comparable construction are known from DE 103 22 231 and DE 103 46 059. These describe magnetic mountings for circular expanders, which are equipped selectively with permanent magnets and/or with electromagnets which allow mounting adaptable to the weight and load of the circular expander and in this case form a sufficient fabric gap. Both the at least one tubular fabric entry part and the at least one tubular fabric exit part are in this case parts which are equipped with magnets and which are surrounded, so as to form a fabric gap, by at least one second tubular fabric entry part and tubular fabric exit part equipped with magnets, the magnets of the parts having an identical polarity. The identical polarity of the magnets arranged opposite one another gives rise to repulsive forces which bring about the formation of the fabric gap.

DE 30 48 957 discloses a circular expander held in suspension as part of a drying plant for textile tubular fabric. This describes a fabric gap capable of being set by the control of electromagnets.

Both the abovementioned solutions have the disadvantage, however, that a stable positioning of the circular expander in its magnetic mounting can be achieved only at the expense of complicated setting work. Moreover, the suspension state which is set in a complicated way and the fabric gap obtained thereby are adversely influenced by external influences, for example by the fabric running through, and are consequently unstable.

The object on which the invention is based is, therefore, to develop a circular expander unit known from the prior art, in such a way that a continuous fabric run-through which can be set in a simple way is made possible, without the quality of the tubular fabric running through being impaired.

The object is achieved, according to the invention, in that a regulatable magnetic mounting is arranged selectively at the entry or at the exit of the circular expander and a conventional roller mounting is arranged at the opposite end of the circular expander.

Advantageously, the tubular fabric entry at the lower end of the vertically arranged circular expander is designed as a magnetic mounting and the opposite upper tubular fabric exit is designed as roller mounting. The attractive magnetic forces at the lower tubular fabric entry of the circular expander hold the latter in a predetermined position, so that a straight first fabric gap is obtained there through which the fabric runs virtually contactlessly and with its quality unimpaired. The friction between the fabric and machine parts is minimized due to the unimpeded entry, such that quality-diminishing distortions and markings in the fabric are avoided.

The first fabric gap is kept constant by regulating the magnetic force at the electromagnets. As a function of the signals from the measurement of the distance sensors, the electromagnets are supplied by a suitable controller with electrical energy such that the predetermined first fabric gap is established. This avoids the need for complicated mechanical aligning and setting work. During production operation, the circular expander is kept in suspension by the magnetic forces. The regulation of the magnetic mounting reacts to changed external influences, such as, for example, a changed fabric tension, from above or below and correspondingly readjusts supply of electrical energy to the magnets.

The roller mounting at the other end of the circular expander ensures sufficient guidance during continuous operation and stabilizes the expander against external influences, such as, for example, forces, caused by irregularities in the fabric tension and/or fabric structure.

The roller mounting can be positioned with the aid of the lifting apparatus. Owing to the optimal positioning of the upper roller mounting with respect to the circular expander arranged beneath it and fixed in the magnetic mounting, the fixing rollers of the roller mounting can be “run free”. The second fabric gap between the fixing rollers and supporting rollers can thus be set. As a result, the surface pressure of the fabric when it runs through the roller mounting is minimized and permanent effects on the quality of the fabric are avoided.

In the event of a failure of the magnetic force, for example due to a power failure at the electromagnets, the roller mounting ensures that the circular expander can be supported with respect to components fixed to the housing.

Further refining features and advantages of the invention may be gathered from the dependent patent claims, the invention description and the drawing figures.

The invention is explained in more detail below with reference to an exemplary embodiment.

In the drawings:

FIG. 1 shows a circular expander unit which is designed on the entry side, at the bottom, with a magnetic mounting and on the exit side, at the top, with a roller mounting,

FIG. 2 shows the detail of the magnetic mounting according to the section A-A in FIG. 3,

FIG. 3 shows a view of the magnetic mounting according to the section B-B in FIG. 2.

The circular expander unit 1 illustrated in FIG. 1 comprises essentially the vertically arranged circular expander 2 of variable diameter, which is mounted via a central telescopic carrier 3 in the tubular fabric entry 4 arranged at the bottom and in the tubular fabric exit 5 arranged at the top.

The tubular fabric 12 is delivered to the circular expander via an entry roller 6 arranged centrally below the circular expander unit 1.

The tubular fabric entry 4 consists essentially of the centrally arranged rotationally symmetrical body 7 which is connected rigidly to the lower end of the central carrier 3 and of the outer magnetic mounting 8 separated by the first fabric gap 14.1.

The tubular fabric exit 5 consists essentially of a roller mounting 9, known per se, consisting of pairs of supporting rollers and fixing rollers, between which a second fabric gap 14.2, through which the tubular fabric is led, is obtained by the circular expander being raised by means of the magnetic forces.

The tubular fabric 12 is spread flat again via a take-off roller 10 arranged centrally above the circular expander unit 1 and is discharged from the circular expander unit.

A lifting apparatus 11 known per. se is mounted at the tubular fabric exit 5. This lifting apparatus is connected to the circular expander 2 via the roller mounting 9. By the roller mounting 9 being raised and lowered, the diameter of the circular expander 2 can be varied.

A locking device, not illustrated, known per se, on the central carrier ensures that the selected diameter of the circular expander is maintained during the guidance of the fabric.

FIG. 2 shows details of the regulated magnetic mounting in the tubular fabric entry according to the section A-A in FIG. 3.

The rotationally symmetrical body 7, which is connected rigidly to the lower end of the central telescopic carrier 3 of the circular expander, is arranged centrally. The magnetic mounting 8 is arranged on the outside, separated by the first fabric gap 14.1. The magnetic mounting 8 consists essentially of two modules 8.1. Each of these modules 8.1 is equipped with electromagnets 8.2 and distance sensors 8.3. The components of the control loop are connected to one another by means of suitable energy and control lines. A power source 8.5 ensures the necessary supply of power to all the control loops. The controller 8.4, illustrated diagrammatically, receives the signals from the measurement of the distance sensors 8.3 and correspondingly to the signals regulates supply of power to the respective electromagnets, so that the predetermined first fabric gap 14.1 is established. The modules 8.1 are connected rigidly to the frame parts 13 fixed to the stand.

FIG. 3 shows details of the magnetic mounting in the tubular fabric entry according to the section B-B in FIG. 2.

The rotationally symmetrical body 7, which in this version is designed as hollow body, is arranged centrally. The magnetic mounting 8 is arranged on the outside, surrounding the body 7, so as to be separated by the first fabric gap 14.1. The magnetic mounting 8 consists essentially of the modules 8.1. Each of the modules 8.1 is equipped with two control loops. Each control loop consists of an electromagnet 8.2, a distance sensor 8.3 and of a controller which is not illustrated here. The modules 8.1 are connected rigidly to the frame parts 13 fixed to the stand.

The structural design of the circular expander 2 is known and therefore is not dealt with in detail here. 

1. A circular expander for treating textile tubular fabric (12), comprising a telescopically displaceable central carrier (3), on which outwardly spreadable supports are articulated, the supports being connected to elements for the longitudinal guidance of the tubular fabric (12), a first device, formed at one end of the central carrier (3) as a tubular fabric entry (4), for delivering the tubular fabric (12), a second device, formed at the other end of the central carrier (3) as a tubular fabric exit (5), for discharging the tubular fabric (12), a lifting apparatus (11), engaging selectively on the first or the second device, for setting the size of the circular spread, and an apparatus, operatively connected to the central carrier (3), for locking the set size of the circular spread, characterized in that, selectively, the first or the second device consists of a preferably rotationally symmetrical body (7) arranged at one free end of the central carrier (3) and of modules (8.1) equipped with electromagnets (8.2), which modules (8.1) partially surround the body (7) so as to form a first fabric gap (14.1), in that each of the modules (8.1) possesses distance sensors (8.3) for regulating the magnetic forces of the electromagnets (8.2), in that the electromagnets (8.2) generate magnetic forces which form a magnetic bearing for the central carrier (3), in that, arranged at the other free end of the central carrier (3) is a roller mounting (9) known per se which consists of pairs of supporting rollers and fixing rollers, between which a second fabric gap (14.2) is formed.
 2. The circular expander as claimed in patent claim 1, characterized in that the rotationally symmetrical body (7) consists completely of ferromagnetic material.
 3. The circular expander as claimed in patent claim 1, characterized in that the rotationally symmetrical body (7) consists partially of ferromagnetic material.
 4. The circular expander as claimed in patent claim 1, characterized in that ferromagnetic elements are integrated in the outer circumference of the rotationally symmetrical body (7).
 5. (canceled)
 6. The circular expander as claimed in patent claim 1, characterized in that the electromagnets (8.2) and the distance sensors (8.3) are integrated in the modules (8.1).
 7. The circular expander as claimed in patent claim 1, characterized in that, in addition to the electromagnets (8.2), permanent magnets are also integrated in the modules (8.1).
 8. The circular expander as claimed in patent claim 1, characterized in that, for setting and regulating the first fabric gap (14.1), at least three distance sensors (8.3) and at least three electromagnets (8.2) are arranged, distributed circumferentially at equal intervals, on the modules (8.1).
 9. The circular expander as claimed in patent claim 1, characterized in that in each case an electromagnet (8.2) and a distance sensor (8.3), together with a controller (8.4), form a control loop. 10 to
 12. (canceled)
 13. The circular expander as claimed in patent claim 1, characterized in that permanent-magnet elements are integrated in the outer circumference of the rotationally symmetrical body (7).
 14. The circular expander as claimed in patent claim 9, characterized in that all the control loops of the magnetic mounting (8) are fed from one power source (8.5).
 15. The circular expander as claimed in patent claim 9, characterized in that each control loop of the magnetic mounting (9) is fed from a specific power source (8.5).
 16. The circular expander as claimed in patent claim 1, characterized in that one controller (8.4) controls all the control loops of the magnetic mounting (8).
 17. The circular expander as claimed in patent claim 16, characterized in that all the control loops of the magnetic mounting (8) are fed from one power source (8.5).
 18. The circular expander as claimed in patent claim 16, characterized in that each control loop of the magnetic mounting (9) is fed from a specific power source (8.5). 